Surina Taneja1, Anupama Rao2, Stephen Nussey3, Alison Leiper2. 1. University College London, London, UK. 2. Department of Haematology, Great Ormond Street Hospital (GOSH) for Children, NHS Foundation Trust, London, UK. 3. Molecular & Clinical Sciences, St George's University of London, London, UK.
Abstract
OBJECTIVE: Testosterone replacement is generally considered likely to be required only at testicular radiation doses in excess of 20Gy. Long-term data are not available for patients receiving 9-14.4Gy as part of Total Body Irradiation in childhood. DESIGN: Retrospective cohort study. DATA COLLECTION: notes review, laboratory results, prescription of testosterone. PATIENTS: Forty-two of 96 boys who received Total Body Irradiation (9-14.4Gy) and Haematopoietic Stem Cell Transplantation for childhood leukaemia at Great Ormond Street Hospital between 1981-2011 and survived >5 years. MEASUREMENTS: The serum concentrations of testosterone and gonadotrophins and the prescription of testosterone were recorded. RESULTS: Of the 42 boys included, 37 (88%) entered puberty spontaneously and 5 required induction. Median length of follow-up was 19.4 years (range 5-33.1). At last follow-up, 23 of the 37 (62%) with spontaneous puberty were receiving testosterone replacement and 4 of the 5 (80%) with induced puberty. CONCLUSION: This study with the benefit of long follow-up indicates that Leydig cell failure occurs with radiation doses <20Gy. It may occur many years after irradiation and mandates long-term screening for hypogonadism.
OBJECTIVE:Testosterone replacement is generally considered likely to be required only at testicular radiation doses in excess of 20Gy. Long-term data are not available for patients receiving 9-14.4Gy as part of Total Body Irradiation in childhood. DESIGN: Retrospective cohort study. DATA COLLECTION: notes review, laboratory results, prescription of testosterone. PATIENTS: Forty-two of 96 boys who received Total Body Irradiation (9-14.4Gy) and Haematopoietic Stem Cell Transplantation for childhood leukaemia at Great Ormond Street Hospital between 1981-2011 and survived >5 years. MEASUREMENTS: The serum concentrations of testosterone and gonadotrophins and the prescription of testosterone were recorded. RESULTS: Of the 42 boys included, 37 (88%) entered puberty spontaneously and 5 required induction. Median length of follow-up was 19.4 years (range 5-33.1). At last follow-up, 23 of the 37 (62%) with spontaneous puberty were receiving testosterone replacement and 4 of the 5 (80%) with induced puberty. CONCLUSION: This study with the benefit of long follow-up indicates that Leydig cell failure occurs with radiation doses <20Gy. It may occur many years after irradiation and mandates long-term screening for hypogonadism.